11. Troubleshooting Mead

Not all mead is well made. A good mead judge should be able to identify, describe, and diagnose common problems in mead, and provide feedback to the meadmaker on possible solutions to the problems. A judge should be careful about becoming a fault-finder by looking for problems where none exist.

This section describes common mead faults and then discusses the more detailed topic of troubleshooting fermentation problems. Some other troubleshooting topics are discussed in the ingredients and process control sections of this document.

Common Mead Faults

Not all possible faults are listed, just the faults listed on the BJCP Mead Scoresheet and the BJCP Mead Exam. Each fault is described in a common format: definition, perception, causes and controls. The definition is the technical definition of the fault. Perception is a description of the fault and the perceptual cues it triggers. Causes and controls describe how the problem can be introduced, and how it might be fixed. Most faults have several possible causes, so judges should resist excessive speculation about how a particular problem was introduced unless the cause is very clear.

Acetic

Definition:	Acetic acid, vinegar. Also known as volatile acidity in winemaking.
How Perceived:	Sharp sourness, vinegary aroma/flavor.
Causes:	Acetobacter infection in the presence of oxygen.
Controls:	Check process and ingredients for sources of infection. Check health/purity of yeast strain. Check for post-fermentation oxidation sources (acetobacter is aerobic). Check handling of fruit additions, since bacteria may be introduced on the fruit skins. Check sanitation of any ingredients added post-fermentation.

Acidic

Definition:	Low pH.
How Perceived:	Tart, sour (basic taste sensation), often with an indication of tart sharpness in aroma.
Causes:	Acid additions, acid level in honey, use of fruit, infection.
Controls:	Check level of acid additions. Check acid levels in honey. Check acid levels in any fruit used (some fruit have higher acid levels, unripe fruit has higher acid levels). Check for infection, particularly lactobacillus. Check sweetness levels and attenuation (an over-attenuated and drier mead than expected might seem acidic if less sweetness is present than what was planned).

Alcoholic

Definition:	Ethanol and higher alcohols.
How Perceived:	Hot, spicy, vinous aromas and flavors, warming or burning mouthfeel and aftertaste, increased bitterness.
Causes:	Too warm a fermentation, insufficient aging and conditioning, unhealthy fermentation, too high a starting gravity or too many fermentables added, over-attenuation, infection.
Controls:	Lower fermentation temperature. Let mead age longer before consuming. Use less fermentables. Use a less attenuative yeast strain. Check yeast health. Use sufficient yeast nutrients. Check for possible infection, which could have caused more attenuation. Stabilize mead to prevent further fermentation.

Cardboard

Definition:	Oxidation.
How Perceived:	Stale, papery, wet cardboard aroma and flavor.
Causes:	Post-fermentation exposure to oxygen.
Controls:	Check for oxygen being introduced into mead post-fermentation. Don’t splash when racking/bottling. Check caps and/or keg seals for good fit. Purge bottles/kegs with CO2 prior to filling. Store mead cool. Drink mead when fresh.

Chemical

Definition:	Chemicals in the mead above taste threshold levels, presence of undesirable chemical substances.
How Perceived:	Chemical, vitamin, nutrient flavors, possibly with bitterness or saltiness.
Causes:	Excessive nutrient use, contaminated water.
Controls:	Use less nutrient additions, check purity and cleanliness of water sources, check use of cleaning chemicals.

Cloudy

Definition:	Obscured with visible particles (of any source).
How Perceived:	Hazy appearance, obscuring particulates, floating flakes (floaties).
Causes:	Yeast remaining in suspension, unfermented honey, clarifiers not working completely, pectin haze.
Controls:	Fine with clarifying agents, troubleshoot stuck fermentation, try different clarifying agents, allow sufficient time for clarifying

Cloying

Definition:	Excessive sweetness unbalanced by acidity or tannin. Also known as “flabby” in the wine-tasting world.
How Perceived:	Overly sweet, syrupy flavor. Heavy body, tongue-coating mouthfeel. Lack of acidity or tannin in flavor. Sometimes accompanied with a raw honey flavor, but this isn’t required.
Causes:	Incomplete fermentation, not enough acid/tanning to balance sweetness.
Controls:	Ferment more completely (troubleshoot fermentation), use less honey or sugary adjuncts, add balancing acid and/or tannin.

Floral

Definition:	Flower-like aromatics.
How Perceived:	Flower blossom, perfume-like aroma and flavor.
Causes:	Honey variety choice.
Controls:	Select a honey variety with the desired varietal characteristics. Not typically a fault, unless in a variety that shouldn’t have these characteristics.

Fruity

Definition:	Estery.
How Perceived:	Fruity aroma or flavor (may include apple, banana, pear, grape, strawberry, citrus, or others).
Causes:	High fermentation temperature, yeast strain, weak or nutrient-deprived fermentation, high gravity, honey variety.
Controls:	Lower fermentation temperature. Try a cleaner yeast strain. Oxygenate must sufficiently. Reduce original gravity. Pitch a sufficient quantity of yeast (avoid yeast stress). Bottle condition and age mead longer at cellar temperatures to reduce esters. Try a different variety of honey.

Harsh

Definition:	Rough, unpleasant flavor and finish.
How Perceived:	A rough, biting or stinging sensation in the mouth, often with excessive bitterness.
Causes:	Excessive acids, alcohols, and/or tannins.
Controls:	Look at sources of acids, alcohols and tannins (see Acidic, Alcoholic, and Tannic descriptions for specific controls).

Metallic

Definition:	Containing metallic ions, especially iron.
How Perceived:	Flavor of iron, copper, coins, or blood.
Causes:	Contaminated water supply, excessive additives, corroded equipment, equipment not properly cleaned and rinsed.
Controls:	Check water for metallic ions. Reduce water salts. Reduce nutrient additions. Check equipment condition for rust. Make sure stainless steel equipment is properly passivated. Fully rinse sanitizer. Try using reverse osmosis water and add salts as needed.

Moldy

Definition:	Mold-like character. TCA (cork taint).
How Perceived:	Stale, moldy, musty cellar-like, earthy, compost-like, mushroom-like aromas and flavors. Wet cardboard and old rag flavors.
Causes:	Oxidation, mold growth, stale water and ingredients, sealing with cork, storage in musty barrels or containers.
Controls:	Avoid oxidation. Check sanitation. Check water for freshness and taste. Use fresh ingredients. Check for mold in corks or use artificial corks.

Phenolic

Definition:	A large group of organic chemicals often having plastic, medicinal or tar-like aromatics.
How Perceived:	Spicy, smoky, plastic, band-aid, medicinal, clove, or vanilla aroma and flavor.
Causes:	Infection with wild yeast. Some honey varieties (eucalyptus, buckwheat, black mangrove) might have some of these flavors. Some spices can be phenolic. Fruit and spices can be an infection source. Oak-aging can introduce phenolics. Water sources.
Controls:	Check for infection. Check yeast strain and health. Check honey variety. Check for oak usage. Check cleanliness of water source.

Sherry

Definition:	Post-fermentation oxidation.
How Perceived:	Sherry, nutty, almond aroma and flavor, possibly with an increased bitterness level.
Causes:	Oxygen introduced into mead post-fermentation.
Controls:	Check for sources of oxygen being introduced after fermentation is complete. Check airlocks to make sure they haven’t dried out. Don’t splash when racking/bottling. Check caps and/or keg seals for good fit. Purge bottles/kegs with CO2 prior to filling. Store mead cool. Drink mead when fresh.

Solvent

Definition:	Fusel alcohols, ethyl acetate.
How Perceived:	Hot burning on palate, harsh finish and aftertaste. Headaches. Nail polish remover or solvent.
Causes:	High fermentation temperatures, stressed fermentation, acetobacter infection, insufficient nutrients.
Controls:	Lower fermentation temperature. Pitch a sufficient quantity of healthy, active yeast. Check for infection. Try a different yeast strain. Ensure sufficient nitrogen-based nutrients are available.

Sulfury

Definition:	Hydrogen sulfide, sulfur dioxide.
How Perceived:	Rotten eggs, burning matches, and other sulfur-based aromas and flavors. Generally unpleasant.
Causes:	Yeast, either a by-product of fermentation or autolysis. Insufficient nutrients (especially nitrogen) can cause the yeast to expel hydrogen sulfide. Sulfur compounds in water supply or in additives. Oxidized sulfur compounds. Excessive sulfite additions.
Controls:	Provide sufficient nitrogen-based nutrients. Check for infection. Check water for excessive sulfates. Check yeast health. Check for yeast autolysis (mead left on yeast too long at warm temperatures). Try another yeast strain. Cut back on sulfite additions.

Sweet

Definition:	Basic taste associated with sugar or honey. Too much sweetness is referred to as a syrupy or cloying quality.
How Perceived:	Sugary or honey-like flavor and aroma.
Causes:	High original gravity, incomplete fermentation, low attenuation. Some honey varieties (e.g., orange blossom, clover) have higher perceived sweetness.
Controls:	Use less honey, encourage a more complete fermentation, aim for a lower finishing gravity, try other honey varieties.

Tannic

Definition:	Polyphenolic. Astringent, bitter plant polyphenols that either bind and precipitate or shrink proteins.
How Perceived:	Astringent, mouth-puckering mouthfeel, lingering harshness, grape skin character, increased bitterness, dry finish.
Causes:	Extraction of tannins from fruit, spices or other ingredients. Excessive tannin additions. Use of oak. Use of tea.
Controls:	Avoid use of raw spices, fruit pith and fruit skins. Reduce tannin additions. Use less oaking.

Thin

Definition:	Lacking in body (also generally lacking in honey flavor impact).
How Perceived:	Thin palate, mouthfeel, and finish. Watery palate impression and body. Insipid character.
Causes:	Over attenuation, poor quality honey, over filtration or excessive fining.
Controls:	Reduce attenuation, back-sweeten with honey, use fewer adjuncts, try a different honey variety, add glycerine (glycerol syrup, wine finishing formula).

Vegetal

Definition:	Smell or taste of plants or green vegetables.
How Perceived:	Cooked, canned or rotten vegetable (cabbage, celery, onion, asparagus, parsnip) aroma and flavor.
Causes:	Bacterial infection in the must.
Controls:	Encourage a fast, vigorous fermentation (use a healthy, active starter to reduce lag time; this is often due to bacterial contamination of must before yeast becomes established). Check sanitation. Check for aged, stale, or old ingredients.

Waxy

Definition:	Characteristic flavor of beeswax.
How Perceived:	Wax-like, tallow, fatty flavor and aroma.
Causes:	Some varieties of honey, oxidized or low quality honey containing excessive fatty acids.
Controls:	Try a different variety of honey. Filter honey. Avoid oxidation.

Yeasty

Definition:	Yeast-like character.
How Perceived:	Bready, sulfury, yeast-like aroma and flavor.
Causes:	Yeast in suspension.
Controls:	Use a more flocculent yeast strain. Allow yeast sufficient time to flocculate. Filter mead or use clarifying agents. Avoid carrying over as much yeast. Age the mead longer. Try another yeast strain.

Troubleshooting Fermentation

The challenge of making mead is achieving the perfect honey fermentation—one that is clean, with zero or absolutely minimal off-flavors. It optimizes the character of a spectacular honey, and yields aromatics and flavors reflecting its finest properties. Simply put, it comes down to a series of steps: pitching a vigorous, healthy yeast population, low lag times, effortless and robust yeast reproduction, successful competition (or K-factor activity), and a steady, healthy fermentation to completion.

A major issue that confronted (and confounded) mead makers until recently was notoriously long fermentation period. Modern research has shown that this is not a normal part of the mead making process, but rather an expected result of not providing an adequate fermentation environment or not providing a sufficient quantity of viable yeast. Although the fermentation rate is somewhat dependent on the honey variety, proper selection of yeast strains, agitation during fermentation, yeast nutrition, and control of pH can dramatically increase the fermentation rate. Avoiding a sluggish fermentation has a major positive effect on flavor.

Even when a fermentation appears healthy at start (and almost always when it doesn’t), a fermentation can stop before it is fully complete. This is known as a “stuck fermentation” and is often characterized by a high specific gravity, a hazy appearance that doesn’t clear over time, a taste of raw honey, a strong sweetness, and a lower-than-expected alcohol level. Fermentations that falter and stick can be extremely difficult to restart, making the maintenance of appropriate fermentation conditions all the more important.

A stuck (or sluggish) fermentation can be caused by one or more of the following factors:

• Not enough viable yeast were pitched. This can occur by not starting with enough yeast, or by damaging the yeast by not adequately handling it before pitching (e.g., failing to rehydrate dry yeast, pitching dry yeast directly into the must, adding the wrong chemicals or additives too early, adding ingredients or additives containing preservatives, etc.).
• Failure to maintain the fermentation in a correct pH range, particularly if the pH drops too low (below 3.2). This can be a natural occurrence, and can result from the use of acidic fruits, the premature use of acid blend, or the failure to buffer the pH with potassium.
• Not providing adequate nutrients for the yeast. Honey is notoriously deficient in nutrients, particularly nitrogen. Yeast also requires many other micronutrients, vitamins, and minerals for proper health. Not adding yeast nutrients, or adding them at the wrong time, can essentially starve the yeast.
• Ironically, too much nutrient can over-stimulate the yeast and drive higher fermentation temperatures that can kill off yeast and create off-flavors.
• Insufficient oxygen in solution during the yeast growth phase. Yeast require oxygen as well as nutrients during the growth phase. If they are unable to find oxygen, they can still ferment but at a drastically reduced rate.
• Failing to maintain an appropriate temperature range for yeast, particularly if the temperature is too cold for the particular strain of yeast. Too cold a temperature will shock the yeast into dormancy, while too hot a temperature can kill off yeast or create off-flavors.
• Too much CO₂ can kill off yeast and reduce overall yeast viability. Failing to stir the must or punch down the fruit cap (in melomels) can lead to toxic CO₂ levels.
• Failing to keep the must properly mixed can result in stratification of the must with different fermentation environments, some of which could be deficient for the yeast. If this occurs early in the fermentation, the results are more pronounced.
• General yeast stress caused by high gravity fermentations can cause fermentation problems (failing to start, sluggish, finishing prematurely). The high osmotic pressure caused by large amounts of honey can press on the cell walls enough to negatively affect fermentation.

Correcting the root cause can help restart the fermentation, but if the yeast are not viable then fresh yeast might need to be introduced. Follow the following process to troubleshoot the fermentation:

1. Check the ambient fermentation temperature and compare against the requirements of the yeast strain being used. Try moving to a 10 °F warmer location and see if the fermentation restarts.
2. Check the pH of the must. If it is below 3.5, adjust upwards using calcium carbonate (CaCO₃), potassium carbonate (K₂CO₃) or a solution of potassium hydroxide (KOH). Adjust until the pH reaches 3.8.
3. Verify that adequate nutrients were added. If not, add more. Start with ¼ tsp Fermaid-K and ½ tsp DAP.
4. Stir the must to make sure it is not stratified and to release CO₂. If making a melomel, punch down the cap.
5. Check the specific gravity of the must. Calculate the alcohol level and verify that it is not above the alcohol tolerance of the yeast.
6. If the specific gravity is not below 50% sugar depletion, then try adding oxygen. However, adding oxygen too late in the process will simply oxidize the finished mead and is not desirable.
7. If none of these methods work, then try repitching fresh yeast. However, don’t just toss it in. A strong fermenter with high alcohol tolerance (like Pasteur Champagne) might be necessary, but following good fermentation management practices is a must. Rehydrate the yeast using GO-FERM. Start feeding the yeast with a weak honey solution and yeast nutrients. Step up the starter twice using must from the stuck fermentation, along with yeast nutrients. Finally add the actively fermenting starter back into the stuck must and stir thoroughly. Cross your fingers and hope for the best.

Troubleshooting Other Common Fermentation Problems

Fermentation never starts. Make sure you pitched a viable starter (it foamed) and provided adequate nutrients. If so, possible problems are: mead is too high a gravity for the yeast, pH is too low for the yeast, or sanitizers, preservatives or other yeast-killing/inhibiting substances are present.

Prolonged, slow fermentation. Probably has insufficient nutrients. People used to think this was normal; it’s not. Can add nutrient and oxygen, then stir. Also check for low pH.